discovering dry eye
Dry Eye Diagnosis: Ask the Patients
BY ROBIN L. CHALMERS, OD, & CAROLYN G.
BEGLEY, OD, MS
Dry eye is a frequent complication of contact lens wear and is also common among non-contact lens wearers. In a recent study conducted by the optometry-based Dry Eye Investigation (DREI), 15 percent of contact lens wearers and 23 percent of non-contact lens wearers were diagnosed with dry eye by their practitioners, with 98 percent in the mild to moderate categories. However, 71 percent of contact lens wearers reported eye dryness while wearing their lenses, but only four percent indicated that they felt eye dryness without lenses. Among 172 patients who discontinued lens wear, the top two reasons were eye dryness and lens discomfort later in the day.
The public health implications of these symptomatic but not necessarily diseased patients were emphasized at a recent National Eye Institute dry eye workshop. Leon Ellwein, OD, estimated that for the Medicare budget alone, nearly four percent of the revenue paid to optometrists was for managing and treating dry eye symptoms. Younger patients report a high prevalence of ocular surface symptoms associated with video display terminals (VDTs). Residents of cold, dry climates such as Toronto or Denver report seasonal symptoms associated with excessively treated indoor air. As our population ages, lives in controlled environments and works while gazing at computer screens, we can expect increased symptoms of eye dryness.
Ask the Patients
Our DREI study group, frustrated with the lack of agreement between signs and symptoms of dry eye, came up with a simple approach for identifying patients with symptoms of dry eye: we asked the patients. In a clinical study of over 1,000 patients at six optometric sites, after asking about eye symptoms, fluctuation throughout the day, health history and other factors, we asked patients: "Do you think you have dry eye" Patients who replied "yes" cited more frequent ocular symptoms than those who replied "no," and their symptoms increased more over the course of a day. Figure 1 shows the morning and evening discomfort reported by contact lens-wearing patients who checked "yes" on the questionnaire. It is evident that the self-diagnosed patients suffered more evening discomfort. Only 37 percent of these patients had been previously diagnosed with dry eye. Interestingly, this self-diagnosed group of patients reported more intense symptoms than those diagnosed with dry eye by practitioners.
The reason why the question, "Do you think you have dry eye?" has diagnostic value is uncertain. Eye dryness is the most frequent symptom among contact lens wearers, whether or not patients are diagnosed by a practitioner. Perhaps forcing patients to decide if they have "dry eye" requires deciding how much the eye discomfort and dryness is bothersome.
The difficulty in diagnosing dry eye highlights our poor understanding of dry eye symptoms and provides evidence for managing conditions that rely on patient symptoms. Patients who think they have dry eye will appreciate your clinical attention to the symptoms they have. They'll be glad you asked.
Dr. Begley is an associate professor at the Indiana University School of Optometry and is also a member of the Graduate Faculty. Dr. Chalmers is a clinical trial consultant with a particular interest in dry eye symptomatology.